An energy services contractor in Sweden was looking for a solution to provide heating and cooling for multiple buildings and offices. The project is part of a large urban development scheme in a residential neighbourhood of Stockholm, involving a large capacity requirement for both heating and cooling.

Sustainability and energy efficiency were a key priority for the contractor who was seeking a solution that could provide heating and cooling with the highest possible Total Efficiency Ratio.


Trane’s heat pump solution was designed to augment the facilities existing HVAC capacities to provide comfort cooling and heating both for comfort and for sanitary water. The specific requirement was for 2MW heating at 68°C and 3.8MW heating at 50°C along with 4MW cooling at 21°C and 560kW cooling at 7°C.

Trane’s recommendation was for a low global warming potential solution with industry-leading efficiencies, including six different units:
• 2 x RTWF 285 water-to-water heat pumps
• 2 x RTWF 165 water-to-water heat pumps
• 2 x RTSF 100 water-to-water heat pumps.

The units all use R1234ze, a refrigerant with near-zero GWP.


Trane provided the commissioning and start-up, with the contractor carrying out the actual installation. The contractor chose Trane thanks to Trane’s reputation for excellent service, robust and reliable equipment and its ability to meet the customer specification for environmentally-friendly simultaneous cooling and heating.

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Project highlights

Location: Sweden

Market application: Comfort heating and cooling

Customer need:

Products installed:
- 4 x Xstream water-to-water Heat pumps
- 1 x City RTSF water-to-water Heat pumps

Featured products

Product name: City™ RTSF Water-to-Water Heat Pump

At a glance:

  • 99.5% reliability rate with screw compressor technology and Adaptive Frequency™ Drive as standard
  • Fully optimized for HFO R1234ze (<1 GWP). Available with R515B as an alternative
  • Minimized refrigerant charge with stainless steel plate heat exchangers

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Featured products

XStream™ RTWF Water-to-Water Heat Pump

Product name: XStream™ RTWF Water-to-Water Heat Pump

At a glance:

  • Market-leading reliability with Trane's renowned, robust screw compressor technology
  • Minimized refrigerant charge with Trane patented CHIL falling film evaporator
  • Series counterflow heat exchanger design

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